  &  \multicolumn{2}{c}{ $\Delta$ log(Coal mining employment)  }  &  \multicolumn{2}{c}{ $\Delta$ log(Coal mining employment)  }    \\  
                    &\multicolumn{1}{c}{Est.}&\multicolumn{1}{c}{S.E.}&\multicolumn{1}{c}{Est.}&\multicolumn{1}{c}{S.E.}\\
 \hline  &&\\   
$\Delta$ log(Agricultural wage)&      -0.475&       0.125&      -0.839&       0.165\\
\addlinespace
$\Delta$ log(Industrial wage)&           .&           .&       0.503&       0.183\\
 && \\  R-squared  &    \multicolumn{2}{c}{.154} & \multicolumn{2}{c}{.249}  \\  Observations &       \multicolumn{2}{c}{58}  & \multicolumn{2}{c}{58} \\ &&\\  \hline   
